Search

Coherent Doppler lidar appears to hold great promise in contributing to the basic store of knowledge concerning flow field characteristics in the nonprecipitous regions surrounding severe storms. The Doppler lidar, through its ability to measure clear air returns, augments the conventional Doppler radar system, which is most useful in the precipitous regions of the storm.A brief description of the Doppler lidar severe storm measurement system is provided along with the technique to be used in performing the flow field measurements. The application of the lidar is addressed, and the planned measurement program is outlined.

Data on the bihemispherical and directional–hemispherical reflectance were measured on a gold standard, a flowers of sulfur secondary standard, glass bead blasted aluminum, and 120 grade aluminum oxide sandpaper. These reflectances were measured for the P(24) and P(20) 10-μm and R(26), R(20), and P(20) 9-μm CO_2 lines. The specular and retroreflection character of scattering from aluminum and sandpaper was evident in our measurements. Our results agree reasonably well with previous measurements. Also when the sphere is irradiated with polarized light no difference was noted in the reflectance, which indicates that the integrating sphere is a depolarizer.

In this paper we determine the coherent response to a 100-μm diam spinning wire as a function of its position within the focal volume of a 10.6-μm coherent Doppler lidar and generate SNR contours both transverse to and along the system line of sight. Application of the contours to single-particle scattering is discussed.

This paper describes recent measurements using coherent Doppler lidars operating at a wavelength of 10.6 μm aboard the NASA Ames Convair 990. The purpose of the measurements was to obtain data on the atmospheric wind fields and the distribution of the backscatter coefficient at 10.6 μm. A description of the instruments is provided detailing the modifications incorporated following the 1981 test flights of the systems. The measurement program is outlined, and preliminary results are discussed.

This brief article introduces some of the papers presented at the OSA Topical Meeting on Coherent Laser Radar: Technology and Applications (July 1987). Plans for the next conference are also discussed.